## From Euclidean Black Hole to Bouncing Cosmology

#### by Mrs. Hagar Meir

*BGU*

##### at Particles and Fields Seminar

Mon, 10 Jul 2023, 14:00

Sacta-Rashi Building for Physics (54), room 207

#### Abstract

Building upon prior research on the SL(2,R)_k/U(1) cigar which by investigating the backreaction of the winding condensate on the cigar background for a large k, a 'puncture' was identified, eliminating the singularity.

Expanding on this research, we aim to extend the punctured cigar geometry to a cosmological context. Through an analytical continuation, we obtained a non-singular FRW metric that mirrors the behavior of the punctured cigar. We wish to establish a connection between the solution and its reflection, representing a dual solution. By employing a coordinate transformation, we derived a metric that coincides with FRW metric from certain points. We argue that the null energy condition in Penrose's singularity theorem does not hold, due to collapse and expansion of the scaling factor, suggesting the existence of a non-singular solution.

Created on 03-07-2023 by Lublinsky, Michael (lublinm)

Updaded on 03-07-2023 by Lublinsky, Michael (lublinm)